90-422: The common bottlenose dolphin or Atlantic bottlenose dolphin ( Tursiops truncatus ) is one of three species of bottlenose dolphin in the genus Tursiops . The common bottlenose dolphin is a very familiar dolphin due to the wide exposure it receives in human care in marine parks and dolphinariums , and in movies and television programs. Common bottlenose dolphins inhabit temperate and tropical oceans throughout
180-475: A junior synonym of Tursiops truncatus . Additionally, bottlenose dolphins along the Pacific coast of Central America were described as T. nuuanu in 1911. A review of T. gillii and T. nuuanu specimens supported T. gillii as a synonym of T. truncatus and T. nuaanu as a unique subspecies. A 2020 study identified four distinct lineages within T. truncatus , each of which could be a distinct subspecies:
270-413: A marine sponge on their rostrum , presumably to protect it when searching for food on the sandy sea bottom. This has only been observed in this bay (first in 1997), and is predominantly practiced by females. A 2005 study showed mothers most likely teach the behavior to their offspring, evincing culture (behavior learned from other species members). Mud plume feeding is a feeding technique performed by
360-646: A 47-month check up, only 20% produced feasible calves, compared to a previous success rate of 83%, in the same area. It is believed that a recent oil spill in this area is partially to blame for these severely low numbers. Dense human development along the eastern coast of Florida and intense agricultural activity have resulted in increased freshwater inputs, changes in drainage patterns, and altered water quality (i.e. chemical contamination, high nutrient input, decreased salinity, decreased sea grass habitat, and eutrophication. High nutrient input from agriculture chemicals and fertilizers causes eutrophication and hypoxia, causing
450-674: A change of water flow pattern from the infant which minimizes separation between the mother and infant, but also increases the mother's surface area and creates a drag for the swimmer. This also leaves less energy to use in swimming speed, foraging, and predator evasion. Adult males live mostly alone or in groups of two to three, and join pods for short periods of time. Adult females and young dolphins normally live in groups of up to 15 animals. Males give strong mutual support if other males help them, even if they are not friends. However, they live in fission-fusion societies of varying group size , within which individuals change associations, often on
540-556: A daily or hourly basis. Group compositions are usually determined by sex, age, reproductive condition, familial relations and affiliation histories. In a dolphin community near Sarasota, Florida , the most common group types are adult females with their recent offspring, older subadults of both sexes, and adult males either alone or in bonded pairs. Smaller groups can join to form larger groups of 100 or more, and occasionally exceed 1,000. The social strategies of marine mammals such as bottlenose dolphins "provide interesting parallels" with
630-424: A fish with its fluke, sometimes knocking it out of the water, using a strategy called "fish whacking". "Strand feeding" is an inherited feeding technique used by bottlenose dolphins near and around coastal regions of Georgia and South Carolina. When a pod finds a school of fish, they will circle the school and trap the fish in a mini whirlpool. Then, the dolphins will charge at the school and push their bodies up onto
720-464: A hooked dorsal fin. The bottlenose is between 2 and 4 m (6.6 and 13.1 ft) long, and weigh between 150 and 650 kg (330 and 1,430 lb). Males are generally larger and heavier than females. In most parts of the world, adult length is between 2.5 and 3.5 m (8.2 and 11.5 ft); weight ranges between 200 and 500 kg (440 and 1,100 lb). Dolphins have a short and well-defined snout that looks like an old-fashioned gin bottle, which
810-448: A human can: the dolphin can store 36 milliliters (ml) of oxygen per kg of body weight, compared with 20 ml per kg for humans. This is an adaptation to diving. The bottlenose dolphin typically rises to the surface to breathe through its blowhole two to three times per minute, although it can remain submerged for up to 20 minutes. Dolphins can breathe while "half-asleep". During the sleeping cycle, one brain hemisphere remains active, while
900-553: A length of just over 4 m (13 ft). Its color varies considerably, is usually dark gray on the back and lighter gray on the flanks, but it can be bluish-grey, brownish-grey, or even nearly black, and is often darker on the back from the rostrum to behind the dorsal fin . This is called countershading and is a form of camouflage . Older dolphins sometimes have a few spots. Bottlenose dolphins can live for more than 40 years. Females typically live 5–10 years longer than males, with some females exceeding 60 years. This extreme age
990-594: A lineage native to the coastal regions of the western North Atlantic (off the coast of North America ), an offshore lineage found worldwide in pelagic ecosystems, a lineage native to the Mediterranean , and a lineage restricted to the Black Sea (previously described as T. truncatus ponticus ). The study noted only weak differentiation between the Black Sea and Mediterranean lineages, and found them to form
SECTION 10
#17327733644911080-478: A mixture of other species including European hake, mackerels ( Scomber colias , S. japonicus and S. scombrus ), European conger , red bandfish ( Cepola macrophthalma ) and European pilchard ( Sardina pilchardus ) are the assimilated diet. Research indicates that the type and range of fish in a dolphin's diet can have a significant impact on its health and metabolism. Dolphins eat 10–20% of their body weight each day, with pregnant and nursing females eating
1170-456: A mud-flat, forcing the fish on the mud-flat, as well. The dolphins then crawl around on their sides, consuming the fish they washed up on shore. This happens only during low tides. One type of feeding behavior seen in bottlenose dolphins is mud ring feeding . Bottlenose dolphins conflict with small-scale coastal commercial fisheries in some Mediterranean areas. Common bottlenose dolphins are probably attracted to fishing nets because they offer
1260-678: A practice known as "strand feeding". Groups of between two and six dolphins are regularly observed creating a bow wave to force the fish out of the water. The dolphins follow the fish, stranding themselves briefly, to eat their prey before twisting their bodies back and forth in order to slide back into the water. While initially documented in South Carolina and Georgia, strand feeding has also been observed in Louisiana, Texas, Baja California, Ecuador, and Australia. Some Mauritanian dolphins cooperate with human fishermen. The dolphins drive
1350-402: A rare form of self-decoration and social object use called grass-wearing. Self-decoration by wearing grass appears to be an attention-getting device rather than purely play and varies from a single blade to large clusters of grass. John's Pass dolphins self-decorate with grass primarily when they form new social groups or engage in procreative activities. Grass-wearing behavior among these dolphins
1440-470: A result of high fish density around the floating cages in the farming area. Fish is one of the main items in the dolphin diet. They also eat shrimps, squid, mollusks, and cuttlefish, and only swallow the soft parts. They eat 22 pounds of fish a day. When they encounter a shoal of fish , they work as a team to herd them towards the shore to maximize the harvest. They also hunt alone, often targeting bottom-dwelling species. The bottlenose dolphin sometimes hits
1530-747: A school of fish towards the shore, where humans await with nets. In the confusion of casting nets, the dolphins catch a large number of fish as well. Intraspecies cooperative foraging has also been observed. These behaviors may also be transmitted via teaching. Controversially, Rendell and Whitehead have proposed a structure for the study of cetacean culture. Similar cases have been observed in Laguna, Santa Catarina in Brazil since during 19th century as well. Near Adelaide , in South Australia , several bottlenose dolphins " tail-walk ", whereby they elevate
1620-741: A season, but inshore populations tend to move less. However, some inshore populations make long migrations in response to El Niño events. The species has occurred as far as 50° north in eastern Pacific waters, possibly as a result of warm water events. The coastal dolphins appear to adapt to warm, shallow waters. It has a smaller body and larger flippers, for maneuverability and heat dispersal. They can be found in harbors, bays, lagoons and estuaries. Offshore dolphins, however, are adapted to cooler, deeper waters. Certain qualities in their blood suggest they are more suited to deep diving. Their considerably larger body protects them against predators and helps them retain heat. Some interactions with humans are harmful to
1710-452: A series of dimples known as vibrissal pits able to sense electric fields. Dolphins have sharp eyesight. The eyes are located at the sides of the head and have a tapetum lucidum , or reflecting membrane, at the back of the retina, which aids vision in dim light. Their horseshoe-shaped, double-slit pupils enable dolphins to have good vision both in air and underwater, despite the different indices of refraction of these media. When under water,
1800-629: A severe reduction in water quality. Excess of phosphorus and nitrogen from these non-point sources deplete the natural cycle of oxygen by overconsumption of algae. Harmful algal blooms are responsible for dead zones and unusual mortality events of common bottlenose dolphins consuming these toxic fish from the brevetoxin produced by the dinoflagellate Karenia brevis . Brevetoxins are neurotoxins that can cause acute respiratory and neurological symptoms, including death, in marine mammals, sea turtles, birds, and fishes. Bottlenose dolphin The bottlenose dolphin
1890-404: A short time. The dolphin's search for food is aided by a form of sonar known as echolocation : it locates objects by producing sounds and listening for the echoes. Clicking sounds are emitted in a focused beam in front of the dolphin. When the clicking sounds hit an object in the water, like a fish or rock, they bounce off and come back to the dolphin as echoes. Echolocation tells the dolphins
SECTION 20
#17327733644911980-524: A sister group to the offshore lineage, indicating that they likely descended from offshore bottlenoses that colonized the Mediterranean and Black Seas. The clade containing the offshore, Mediterranean, and Black Sea populations was sister to the western North Atlantic lineage, indicating deep divergence between the two. An analysis of the morphology, genetics, and evolutionary divergence of the western North Atlantic coastal and offshore ecotypes supported
2070-554: A small community of bottlenose dolphins over shallow seagrass beds (less than 1 m) in the Florida Keys in the United States. The behavior involves creation of a U-shaped plume of mud in the water column and then rushing through the plume to capture fish. Along the beaches and tidal marshes of South Carolina and Georgia in the United States, bottlenose dolphins cooperatively herd prey fish onto steep and sandy banks in
2160-833: A specific facility. The environmental impact of the Deepwater Horizon oil spill caused a direct impact and still serves as a long-term impact of future populations. Common bottlenose dolphins use these important habitats for calving, foraging, and feeding. Environmental impacts or changes from chemicals or marine pollution can alter and disrupt endocrine systems, affecting future populations. For example, oil spills have been related to lung and reproductive diseases in female dolphins. A recent study suggested signs of lung disease and impaired stress in 32 dolphins that were captured and assessed in Barataria Bay, Louisiana, US. Out of these 32 dolphins, 10 were found pregnant and, upon
2250-764: A spike in attacks on swimmers in Mihama, a Japanese seaside town. The North Sea , Baltic , Mediterranean and Black Sea populations of the common bottlenose dolphin are listed in Appendix II to the Convention on the Conservation of Migratory Species of Wild Animals (CMS) of the Bonn Convention , since they have an unfavorable conservation status or would benefit significantly from international cooperation organized by tailored agreements. The species
2340-541: A swimmer and injuring many others, which earned it the nickname of killer dolphin. Fungie was another solitary male bottlenose, living in close contact with humans in Dingle Harbour, Ireland , from 1983 until his disappearance in 2020. He became a symbol of the town, although some doubt exists over whether he was a single dolphin. A lonely and potentially sexually frustrated dolphin was blamed in August 2024 for
2430-493: A synonym of T. truncatus , while T. nuuanu was recognized as a subspecies. In general, genetic variation between populations is significant, even among nearby populations. As a result of this genetic variation, other distinct species currently considered to be populations of common bottlenose dolphin are possible. Much of the discussion and doubts about its taxonomy is related to the existence of two ecotypes of bottlenose dolphins in many part of its distribution. For example,
2520-628: A third distinct species was described, the Burrunan dolphin ( T. (aduncus) australis ), found in the Port Phillip and Gippsland Lakes areas of Victoria , Australia, after research showed it was distinct from T. truncatus and T. aduncus , both in morphology and genetics. Also, evidence has been accumulating to validate the existence of a separate species, Lahille's bottlenose dolphin, T. gephyreus , that occurs in coastal waters of Argentina, Uruguay and southern Brazil. Other sources accept
2610-517: A uniquely identifying, frequency-modulated narrow-band signature vocalization ( signature whistle ). Signature whistles, which are in a higher frequency range than humans can hear, have an important role in facilitating mother–calf contact. In the Sarasota Dolphin Research Program's library of recordings were 19 female common bottlenose dolphins ( Tursiops truncatus ) producing signature whistles both with and without
2700-879: A wide variety of fishes. It does not chew its food, instead swallowing it whole. Dolphin pods often work as a team to harvest schools of fish, though they also hunt individually. Dolphins search for prey primarily using echolocation , which is a form of sonar . The diet of common bottlenose dolphin pods varies depending on area. Along the U.S. Atlantic coast , the main prey includes Atlantic croakers ( Micropogonias undulatus ), spot ( Leiostomus xanthurus ) and American silver perch ( Bairdiella chrysoura ), while in South Africa, African maasbankers ( Trachurus delagoa ), olive grunters ( Pomadasys olivaceus ), and pandora ( Pagellus bellottii ) are common bottlenose dolphin's typical prey. Their hunting strategies depend on what they are eating; for example, with fish they will circle
2790-463: Is a toothed whale in the genus Tursiops . They are common, cosmopolitan members of the family Delphinidae , the family of oceanic dolphins . Molecular studies show the genus contains three species : the common bottlenose dolphin ( Tursiops truncatus ), the Indo-Pacific bottlenose dolphin ( Tursiops aduncus ), and Tamanend's bottlenose dolphin ( Tursiops erebennus ). Others, like
Common bottlenose dolphin - Misplaced Pages Continue
2880-463: Is a local behavioral tradition that could constitute a cultural difference from other communities. Some researchers hypothesize that the number of nerve cells ( neurons ) in the cortex of the brain predicts intelligence in mammals . A 2019 study estimated the number of neurons in the cerebral cortex of three common bottlenose dolphins and found numbers ranging from 11.7 to 15.2 billion neurons. The human average being approximately 16 billion, this
2970-579: Is energetically expensive. Males have large testes in relation to their body size. During the breeding season , males compete for access to females. Such competition can take the form of fighting other males or of herding females to prevent access by other males. Male Sarasota Bay common bottlenose dolphins with the defensive advantages of male pair-bonding range more widely than unpaired males, and encounter more unrelated females. In Shark Bay, male Indo-Pacific bottlenose dolphins have been observed working in pairs or larger groups to follow and/or restrict
3060-638: Is followed by rapid conception (1–2 months), whereas conception is delayed (2–9 months) if calf loss occurs between January and July. Weaning ages ranged from 2.7 to 8.0 years, but 66.7% (42 calves) were weaned by their fourth birthday. Females tended to wean mid-pregnancy. Group size was unrelated to water depth or female reproductive success, but reproductive success was predicted by water depth. Shallow water may allow mothers and calves to detect and avoid predatory sharks. Alternatively, or additionally, prey density may be higher in shallow water compared to deep water. Georgetown University professor Janet Mann argues
3150-599: Is included in Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning international trade (including in parts/derivatives) is regulated. Estimated population of a few specific areas are including: The species is covered by the Agreement on Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas ( ASCOBANS ), the Agreement on the Conservation of Cetaceans in
3240-608: Is likely within the range found in the human population. Bottlenose dolphins have a lifespan of 40–60 years. Females can outlive males and live for 60 years or more. Dolphins start to reproduce aged 5 to 15 years. The bottlenose dolphin has a single blowhole located on the dorsal surface of the head consisting of a hole and a muscular flap. The flap is closed during muscle relaxation and opens during contraction. Dolphins are voluntary breathers, who must deliberately surface and open their blowholes to get air. They can store almost twice as much oxygen in proportion to their body weight as
3330-787: Is not a typical characteristic of most members of the species). Numerous investigations of bottlenose dolphin intelligence have been conducted, examining mimicry , use of artificial language , object categorization, and self-recognition . They can use tools (sponging; using marine sponges to forage for food sources they normally could not access) and transmit cultural knowledge from generation to generation, and their considerable intelligence has driven interaction with humans. Bottlenose dolphins gained popularity from aquarium shows and television programs such as Flipper . They have also been trained by militaries to locate sea mines or detect and mark enemy divers. In some areas, they cooperate with local fishermen by driving fish into their nets and eating
3420-411: Is popular in aquarium shows and television programs such as Flipper . It has also been trained for military uses such as locating sea mines or detecting and marking enemy divers, as for example in the U.S. Navy Marine Mammal Program . In some areas, they cooperate with local fishermen by driving fish toward the fishermen and eating the fish that escape the fishermen's nets. As a very social species,
3510-504: Is rare and less than 2% of all Bottlenose dolphins will live longer than 60 years. Bottlenose dolphins can jump to a height of 6 metres (20 feet) in the air. Their elongated upper and lower jaws form what is called a rostrum, or snout, which gives the animal its common name. The real, functional nose is the blowhole on top of its head; the nasal septum is visible when the blowhole is open. Bottlenose dolphins have 18 to 28 conical teeth on each side of each jaw. The flukes (lobes of
3600-592: Is reached, and there is no recorded menopause in the bottlenose dolphin species. Sexual maturity varies by population, and ranges from 5–14 years of age; sexual maturity occurs between 8 and 13 years for males and 5 to 10 years for females. The average life span of common bottlenose dolphins is at least 40 years old and up to 60 years old, with females typically living longer than males. but in captivity they have been known to live to up to 51 years old. The main threats to bottlenose dolphins depends on their geographic range. Dolphins living in shallow coastal waters tend to be
3690-407: Is the source for their common name. Like all whales and dolphins, though, the snout is not a true nose; the nose instead evolved into the blowhole on the top of their heads. Their necks are more flexible than other dolphins' due to five of their seven vertebrae not being fused together like in other dolphins. Until 1998, all bottlenose dolphins were considered one species T. truncatus. That year,
Common bottlenose dolphin - Misplaced Pages Continue
3780-537: The Burrunan dolphin ( Tursiops (aduncus) australis ), may be alternately considered their own species or be subspecies of T. aduncus . Bottlenose dolphins inhabit warm and temperate seas worldwide, being found everywhere except for the Arctic and Antarctic Circle regions. Their name derives from the Latin tursio (dolphin) and truncatus for the truncated teeth (the type specimen was old and had worn down teeth; this
3870-513: The Indo-Pacific bottlenose dolphin ( T. aduncus ) was recognized as a separate species. The two species are thought to have split during the mid- Pleistocene , about 1 million years ago. Currently, four common bottlenose dolphin subspecies are recognized: Bottlenose dolphins along the southern California and Baja California coasts were previously recognized as the Pacific bottlenose dolphin, T. t. gillii , originally described as distinct species T. gillii . The name has since been reclassified as
3960-482: The dorsal fins making them individually identifiable. These unique identifiers are universally used in studies around the globe. Common bottlenose dolphin signature whistles, which are in a higher frequency range than humans can hear, have an important role in facilitating mother–calf contact. In the Sarasota Dolphin Research Program's library of recordings were 19 female common bottlenose dolphins ( Tursiops truncatus ) producing signature whistles both with and without
4050-454: The 1950s, no "dolphin language" has been found. However, Herman , Richards, and Wolz demonstrated comprehension of an artificial language by two bottlenose dolphins (named Akeakamai and Phoenix) in the period of skepticism toward animal language following Herbert Terrace 's critique. Cognitive abilities that have been investigated include concept formation , sensory skills, and mental representations. Such research has been ongoing since
4140-485: The 1970s. This includes: acoustic and behavioral mimicry, comprehension of novel sequences in an artificial language , memory , monitoring of self behavior, discrimination and matching, comprehension of symbols for various body parts, comprehension of pointing gestures and gaze (as made by dolphins or humans), mirror self-recognition , and numerical values. At least some wild bottlenose dolphins use tools. In Shark Bay , off Western Australia , dolphins place
4230-626: The Black Sea, Mediterranean Sea and Contiguous Atlantic Area ( ACCOBAMS ), the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region, and the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia. Common bottlenose dolphins are the most common apex predators found in coastal and estuarine ecosystems along
4320-578: The Eastern Tropical Pacific bottlenose dolphin ( T. t. nuuanu ). The IUCN, on their Red List of endangered species, currently recognises only two species of bottlenose dolphins. The American Society of Mammalogists also recognizes only two species. While acknowledging the studies describing T. australis , it classifies it within T. aduncus . Some recent genetic evidence suggests the Indo-Pacific bottlenose dolphin belongs in
4410-503: The Pacific bottlenose dolphin ( T. t. gillii or T. gillii ), that inhabits the Pacific, and has a black line from the eye to the forehead. T. gillii , first described in 1873, is currently considered a junior synonym of T. truncatus . Additionally, T. nuuanu was described in 1911 for bottlenose dolphins along the Pacific coast in Central America. An analysis of T. gillii and T. nuuanu specimens supported T. gillii as
4500-681: The behaviour has continued through generations until 2022. A study conducted by the University of Chicago showed that bottlenose dolphins can remember whistles of other dolphins they had lived with after 20 years of separation. Each dolphin has a unique whistle that functions like a name, allowing the marine mammals to keep close social bonds. The new research shows that dolphins have the longest memory yet known in any species other than humans . The bottlenose dolphins of John's Pass in Boca Ciega Bay, St. Petersburg, Florida , exhibit
4590-425: The brain which can be interpreted at a frequency of 120 kHz . This allows dolphin to know the location, shape and size of objects aiding in navigation, communication, hunting, and awareness of predators nearby. Dolphins can emit both high and low frequency sounds, but lower frequencies travel best in the water allowing for the best results while using echolocation. Its diet consists mainly of eels, squid, shrimp and
SECTION 50
#17327733644914680-527: The brain. Bottlenose dolphins are able to detect salty, sweet, bitter ( quinine sulphate ), and sour ( citric acid ) tastes, but this has not been well-studied. Anecdotally, some individuals in captivity have been noted to have preferences for food fish types, although it is not clear if taste mediates this preference. In 2022, a study at the University of St Andrews in Scotland found that dolphins were able to identify their "friends" and family members by
4770-495: The child to pay attention, long-term bonding, and promoting the development of lifelong vocal learning , with parallels in these bottlenose dolphins in an example of convergent evolution . Mating behavior of the bottlenose dolphin is polygamous . Although they can breed throughout the year, it mostly occurs in spring, and with a 12 month gestation period mating season and birthing season overlap. Males form alliances, or pair bonds, to seek an estrous female and they attempt to breed
4860-796: The child to pay attention, long-term bonding, and promoting the development of lifelong vocal learning , with parallels in these bottlenose dolphins in an example of convergent evolution . Researchers from the Bottlenose Dolphin Research Institute (BDRI), based in Sardinia (Italy) have now shown whistles and burst pulsed sounds are vital to the animals' social life and mirror their behaviors. The tonal whistle sounds (the most melodious ones) allow dolphins to stay in contact with each other (above all, mothers and offspring), and to coordinate hunting strategies. The burst-pulsed sounds (which are more complex and varied than
4950-505: The coastal form as being a distinct species. While the offshore type was retained within T. truncatus , the coastal dolphins are now recognized as Tamanend's bottlenose dolphin ( T. erebennus ). The common bottlenose dolphin has a larger brain than humans. Many investigations of bottlenose intelligence include tests of mimicry, use of artificial language, object categorization, and self-recognition. This intelligence has driven considerable interaction with humans. The common bottlenose dolphin
5040-463: The coastal form while the offshore form was retained in T. truncatus . The Society for Marine Mammalogy 's Committee on Taxonomy presently recognizes three species of bottlenose dolphin: T. truncatus , T. aduncus , and T. erebennus . They also recognize three subspecies of common bottlenose dolphin in addition to the nominotypical subspecies : the Black Sea bottlenose dolphin ( T. t. ponticus ), Lahille's bottlenose dolphin ( T. t. gephyreus ), and
5130-474: The common bottlenose dolphin lives in groups called pods that typically number about 15 individuals, but group size varies from pairs of dolphins to over 100 or even occasionally over 1,000 animals for short periods of time. Their geographic range dictates a lot of their behaviors including the densities of dolphins while travelling. The types of groups include: nursery groups, juvenile groups, and groups of adult males. Male dolphins tend to form pair bonds, which are
5220-626: The dolphins. Dolphin hunting industry exists in multiple countries including Japan, where common bottlenose dolphins are hunted for food annually in the town of Taiji , and the Faroe Islands . Also, dolphins are sometimes killed inadvertently as a bycatch of tuna fishing. Tião was a well-known solitary male bottlenose dolphin that was first spotted in the town of São Sebastião in Brazil around 1994 and frequently allowed humans to interact with him. The dolphin later became infamous for killing
5310-463: The eyeball's lens serves to focus light, whereas in the in-air environment, the typically bright light serves to contract the specialized pupil, resulting in sharpness from a smaller aperture (similar to a pinhole camera ). By contrast, a bottlenose's sense of smell is poor, because its blowhole, the analog to the nose, is closed when underwater and it opens only for breathing. Like other toothed whales , it has no olfactory nerves or olfactory lobe in
5400-454: The fact that the Tursiops dolphins might consist of more than one species, as there is extensive variation in color and morphology along its range. In the past, most studies used morphology to evaluate differences between and within species, but in the late 20th century, combining morphological and molecular genetics allowed much greater insight into this previously intractable problem. Since
5490-648: The females are not in their estrous cycles and cannot produce young, suggesting they may mate for pleasure . The gestation period averages 12 months. Births can occur at any time of year, although peaks occur in warmer months. The young are born in shallow water, sometimes assisted by a (possibly male) "midwife", and usually only a single calf is born. Twins are possible, but rare. Newborn bottlenose dolphins are 0.8 to 1.4 m (2.6 to 4.6 ft) long and weigh 9 to 30 kg (20 to 66 lb), with Indo-Pacific bottlenose dolphin infants being generally smaller than common bottlenose dolphin infants. To accelerate nursing,
SECTION 60
#17327733644915580-600: The fish that escape. Some encounters with humans are harmful to the dolphins: people hunt them for food, and dolphins are killed inadvertently as a bycatch of tuna fishing and by getting caught in crab traps . Bottlenose dolphins have the third largest encephalization levels of any mammal on Earth (humans have the largest, followed by Northern Right whale dolphins ), sharing close ratios with those of humans and other cetaceans , while being twice as high of other great apes . This more than likely contributes to their high intelligence . Scientists have been long aware of
5670-537: The genital slit. The ability to stow their reproductive organs (especially in males) allows for maximum hydrodynamics. The breeding season produces significant physiological changes in males. At that time, the testes enlarge, enabling them to hold more sperm. Large amounts of sperm allow a male to wash away the previous suitor's sperm, while leaving some of his own for fertilization. Also, sperm concentration markedly increases. Having less sperm for out-of-season social mating means it wastes less. This suggests sperm production
5760-595: The genus Stenella , since it is more like the Atlantic spotted dolphin ( Stenella frontalis ) than the common bottlenose dolphin. However, more recent studies indicate that this is a consequence of reticulate evolution (such as past hybridization between Stenella and ancestral Tursiops ) and incomplete lineage sorting , and thus support T . truncatus and T. aduncus belonging to the same genus. Bottlenose dolphins have been known to hybridize with other dolphin species. Hybrids with Risso's dolphin occur both in
5850-467: The late 1990s and early 2000s, most researchers acknowledged the existence of two species: the common bottlenose dolphin ( T. truncatus ), found in coastal and oceanic habitats of most tropical to temperate oceans, and the Indo-Pacific bottlenose dolphin ( T. aduncus ), that lives in coastal waters around India , northern Australia, South China, the Red Sea , and the eastern coast of Africa. In 2011,
5940-586: The most while keeping other males away from viable females. For a chance to mate with the female, males separate the female from her home range. Females bear a calf every three to six years. After a year-long gestation period, females bear a single calf. Newborn calves are between 0.8 and 1.4 m (2 ft 7 in and 4 ft 7 in) long and weigh between 15 and 30 kg (33 and 66 lb). The calf's suckling lasts between 18 and 20 months and they are weaned between three and eight years of age. Females typically reproduce every 3 to 6 years when sexual maturity
6030-495: The most. Dolphins use sound for communication, including squeaks emitted from the blowhole , whistles emitted from nasal sacs below the blowhole, and sounds emitted through body language, such as leaping from the water and slapping their tails on the water. The dolphins address each other individually by matching each other's signature whistle . While communicating with each other, bottlenose dolphins grab ahold of each other with their teeth, which forms unique knicks and notches on
6120-419: The mother can eject milk from her mammary glands . The calf suckles for 18 months to up to 8 years, and continues to closely associate with its mother for several years after weaning. Females sexually mature at ages 5–13, males at ages 9–14. Females reproduce every two to six years. Reproduction is moderately seasonal (September–January), peaking from October to December. Calf loss between August and December
6210-432: The movement of a female for weeks at a time, waiting for her to become sexually receptive . These coalitions, also known as male reproductive alliances , will fight with other coalitions for control of females. Humans and bottlenose dolphins are the only species that share this type of "gang formation" habit as a form of cooperation. Mating occurs belly to belly. Dolphins have been observed engaging in intercourse when
6300-564: The other hemisphere shuts down. The active hemisphere handles surfacing and breathing behavior. The daily sleeping cycle lasts for about 8 hours, in increments of minutes to hours. During the sleeping cycle, they remain near the surface, swimming slowly or "logging", and occasionally closing one eye. Both sexes have genital slits on the underside of their bodies. The male can retract and conceal his penis through his slit. The female's slit houses her vagina and anus. Females have two mammary slits, each housing one nipple , one on each side of
6390-441: The presence of their dependent calf. In all 19 cases, the mother dolphin changed the same signature whistle when the calf was present, by reaching a higher frequency, or using a wider frequency range. Similarly, humans use higher fundamental frequencies and a wider pitch range to inflect child–directed speech (CDS). This has rarely been discovered in other species. The researchers stated that CDS benefits for humans are cueing
6480-435: The presence of their dependent calf. In all 19 cases, the mother dolphin changed the same signature whistle when the calf was present, by reaching a higher frequency, or using a wider frequency range. Similarly, humans use higher fundamental frequencies and a wider pitch range to inflect child–directed speech (CDS). This has rarely been discovered in other species. The researchers stated that CDS benefits for humans are cueing
6570-693: The school and use their echolocation to feed on them one by one. They can also stun fish using sonar or smash them into corals depending on their speed. According to combined stomach content and stable isotope analyses in the Gulf of Cádiz , although European conger ( Conger conger ) and European hake ( Merluccius merluccius ) are most important prey of common bottlenose dolphins, mass-balance isotopic mixing model (MixSIAR), using δ13C and δ15N shows that Sparidae species; seabreams ( Diplodus annularis and D. bellottii ), rubberlip grunt ( Plectorhinchus mediterraneus ), and common pandora , ( Pagellus erythrinus ) and
6660-617: The sensitivity of the sound receptor.) The interclick interval also decreases as the animal nears the target. Evidently, the dolphin waits for each click's echo before clicking again. Echolocation details, such as signal strength, spectral qualities, and discrimination, are well understood by researchers. Bottlenose dolphins are also able to extract shape information, suggesting they are able to form an "echoic image" or sound picture of their targets. They also have electroreception . The calves are born with two slender rows of whiskers along their snout, which fall off soon after birth, leaving behind
6750-411: The shape, size, speed, distance, and location of the object. To hear the returning echo, they have two small ear openings behind the eyes, but most sound waves are transmitted to the inner ear through the lower jaw. As the object of interest is approached, the echo becomes booming, and the dolphins adjust by decreasing the intensity of the emitted sounds. (This contrasts with bats and sonar, which reduce
6840-468: The social strategies of elephants and chimpanzees. Bottlenose dolphins studied by Bottlenose Dolphin Research Institute researchers off the island of Sardinia show random social behavior while feeding, and their social behavior does not depend on feeding activity. In Sardinia, the presence of a floating marine fin-fish farm has been linked to a change in bottlenose dolphin distribution as
6930-461: The southern coast of the US, thus serve as an important indicator species of bioaccumulation and health of the ecosystem. It is believed that some diseases commonly found in dolphins are related to human behaviors, such as water pollution. Water pollution is linked to point and non-point source pollution. Point source pollution comes from a single source such as an oil spill and/or chemical discharge from
7020-526: The strong personal behavior among male calves is about bond formation and benefits the species in an evolutionary context. She cites studies showing these dolphins as adults are inseparable, and that early bonds aid protection, as well as in locating females. Female bottlenose dolphins have to expend additional energy in carrying out parental care, e.g. , infant-carrying behavior. Dolphins do not physically hold their infants but line up in an echelon position with infants swimming beside them. This position creates
7110-440: The strongest of dolphin bonds, while females stay with their calves for 3–8 years and then tend to stay in social groups. Dolphin use of their blowholes and nasal sacs to communicate and their ability to echolocate with their melon are keys to their success. Echolocation uses sound waves that are emitted and received to understand their surroundings. As sound waves are emitted they are bounced back and received as nerve impulses in
7200-538: The tail) and dorsal fin are formed of dense connective tissue and do not contain bone or muscle . The dorsal fin usually shows phenotypic variations that help discriminate among populations. The animal propels itself by moving the flukes up and down. The pectoral flippers (at the sides of the body) are for steering; they contain bones homologous to the forelimbs of land mammals. A bottlenose dolphin discovered in Japan has two additional pectoral fins, or "hind legs", at
7290-649: The tail, about the size of a human's pair of hands. Scientists believe a mutation caused the ancient trait to reassert itself as a form of atavism . In colder waters, they have more body fat and blood, and are more suited to deeper diving. Typically, 18%–20% of their body weight is blubber. Most research in this area has been restricted to the North Atlantic Ocean . Bottlenose dolphins typically swim at 5 to 11 km/h (1.4 to 3.1 m/s), but are capable of bursts of up to 29 to 35 km/h (8.1 to 9.7 m/s). The higher speeds can only be sustained for
7380-481: The taste of their urine in the water. Bottlenose dolphins communicate through burst pulsed sounds, whistles, and body language. Examples of body language include leaping out of the water, snapping jaws, slapping the tail on the surface and butting heads. Sounds and gestures help keep track of other dolphins in the group, and alert other dolphins to danger and nearby food. Lacking vocal cords , they produce sounds using six air sacs near their blow hole. Each animal has
7470-443: The top predator with the exception of young dolphins having to be protected from sharks by their moms. Dolphin communities out in the deep ocean have more threats with shark attacks but living in pods allows them to survive. Other predators, mainly impacting newborns, include sting rays and orcas. Although dolphins inhabit every ocean of the planet including some rivers and other ecosystems, the common bottlenose dolphin can be found in
7560-427: The two ecotypes of the common bottlenose dolphin within the western North Atlantic are represented by the shallower water or coastal ecotype and the more offshore ecotype. Their ranges overlap, but they have been shown to be genetically distinct. In 2022, Costa et al. established morphologic, genetic, and evolutionary divergence between the two ecotypes in the western North Atlantic, resurrecting Tursiops erebennus for
7650-437: The upper part of their bodies vertically out of the water, and propel themselves along the surface with powerful tail movements. Tail-walking mostly arises via human training in dolphinaria. In the 1980s, a female from the local population was kept at a local dolphinarium for three weeks, and the scientist suggests she copied the tail-walking behavior from other dolphins. Two other wild adult female dolphins copied it from her, and
7740-463: The warmer oceanic regions specifically in temperate, subtropical, and tropical oceans around the world. The global population has been estimated at 600,000. Some bottlenose populations live closer to the shore (inshore populations) and others live further out to sea (offshore populations). Generally, offshore populations are larger, darker, and have proportionally shorter fins and beaks. Offshore populations can migrate up to 4,200 km (2,600 mi) in
7830-451: The whistles) are used "to avoid physical aggression in situations of high excitement", such as when they are competing for the same piece of food, for example. The dolphins emit these strident sounds when in the presence of other individuals moving towards the same prey. The "least dominant" one soon moves away to avoid confrontation. Other communication uses about 30 distinguishable sounds, and although famously proposed by John C. Lilly in
7920-615: The wild and in captivity. The best known hybrid is the wholphin , a false killer whale -bottlenose dolphin hybrid. The wholphin is fertile, and two currently live at the Sea Life Park in Hawaii. The first was born in 1985 to a female bottlenose. Wholphins also exist in the wild. In captivity, a bottlenose dolphin and a rough-toothed dolphin hybridized. A common dolphin -bottlenose dolphin hybrid born in captivity lives at SeaWorld California. Other hybrids live in captivity around
8010-733: The world and in the wild, such as a bottlenose dolphin-Atlantic spotted dolphin hybrid. Bottlenose dolphins appeared during the Miocene . Known fossil species include Tursiops osennae (late Miocene to early Pliocene ) from the Piacenzian coastal mudstone, and Tursiops miocaenus (Miocene) from the Burdigalian marine sandstone, all in Italy. The bottlenose dolphin weighs an average of 300 kg (660 lb), but can range from 150 and 650 kg (330 and 1,430 lb). It can reach
8100-419: The world, absent only from polar waters. While formerly known simply as the bottlenose dolphin , this term is now applied to the genus Tursiops as a whole. As considerable genetic variation has been described within this species, even between neighboring populations, many experts think additional species may be recognized. Common bottlenose dolphins have a grey coloring, a short beak, a single blowhole, and
#490509